Cylinder construction



Aug. 14, 1951 R. M. MAGNUSON 2,563,949

CYLINDER CONSTRUCTION Filed Sept. 14, 1946 2 Sheeis-Sheet 1 FIE E I ugly||u INVENTOYR I 5 B pay M Maj/71150 4/ 73 33 F I I5 EA.

ATTORNEY Patented Aug. 14, 195i ifihit UNITED STATES PATENT OFFICE2,5'63,949- I CYLINDER CONSTRUCTION Roy M. Magnuson, Campbell, Calif. 1Application September 14, 1946, Serial No. 697,066

9 Claims. 1

This invention relates to pumps and is concerned more particularly withpumps of the reciprocating type employing a piston especially adaptedfor high pressure operation with liquids containing abrasives.

It is a general object of the invention to provide an improvedpiston-type pump. 1

Another object of the invention is to provide an improved pump of theabove character for use with abrasive-containing liquids;

A further object of the invention is to provide a pump of the abovecharacter having a quick replaceable pump packing.

Another object of the invention is to provide for lubrication of a pumppacking of the type employing pressure sealing end faces.

Another object of the invention is to provide a pump of the abovecharacter in which the mechanical drive portion of the pump is shieldedfrom leakage. fluid of the hydraulic portion thereof.

A further object of the invention is to provide a hydraulic assembly ofa piston pump which can be disassembled readily for cleaning.

Another object of the invention is to provide a pump of the opposedpiston type in which the drive is transmitted to a pair of opposedpistons in a simple and advantageous manner.

Another object of the invention is to provide improved means forpreventing contamination of the lubricating oil of'a pump drivemechanism by the liquid being pumped.

A further object of the invention is to provide an improved check val econstruction for the pump. I I

A further object of the invention is to provide an improved pump packingunit which is supported independently of the piston and the cylinder ofthe pump.

Other objects and advantages of the invention will be apparent from thefollowing description pump taken in planes indicated in line 4-4 inFigure 1.

Figure 5 is an end elevational view of the upper or hydraulic portion ofthe pump.

Figure 6 is a fragmentary sectional view taken as indicated by the line6-6 in Figure 1.

Figure 7 is a fragmentary sectional view showing an enlargement portionof the pump packing.

Figure 8 is an enlarged sectional view of the check valve and itsmounting.

Referring to the drawings, the pump includes a crankcase III of castconstruction which houses the pump drive mechanism and a cylinder casell of cast construction which houses the hydraulic mechanism andwhichvis secured on the crankcase by four cap screws l2. The crankcaseIll (Figures 2, 3 and 4) is provided with opposite bosses l3 in which adrive shaft I4 is journalled by means of sleeve bearings IS. The bossesl3 are apertured at IT for admission of splashed oil to the bearings.Between the bearings iii a drive pinion I8 is pinned or otherwisesecured on the shaft 14. The drive pinion I8 (Figures 2 and 3) mesheswith a drive gear 19 .whose integrally formed hub la is journalled bysleeve bearings 2| on a supporting shaft 22 which is secured in bosses24 of the crankcase. The shaft 22 is grooved adjacent its ends at 22a toregister with oil receiving pockets 23 in the bosses 24. The shaft 22 isthreaded at each end to receive a cap screw 26 which serves to secure inplace and tighten a rubber securing and sealing ring or washer 21 bymeans of a metallic washer 28. The sealing ring 21 is expanded forpressure engagement within the apertured boss 24 to effect a tight sealand frictionally hold the shaft 22 against rotative and endwisedisplacement. The shaft 22 is apertured axially at 22b and radially at22c for feeding of lubricant to the bearings 2|.

' The drive from the drive gear l9 (Figures 2 and 3) is transmitted bymeans of an eccentric I 9b formed integrally with the gear l9 and itshub I9a. Engaged about the eccentric l9b is an eccentric follower 3|which is lubricated through a passage I in the eccentric I912. Theeccentric follower 3| (Figure 2) is connected by a pivot pin 32 to abellcrank drive element 33 which is mounted on a shaft 35 secured withinopposed bosses 34 of the crankcase by securing nuts 30 and sealing andsecuringLrings 30a similar to the nuts 26 and rings 21 previouslyreferred to. In this case the right-hand nut 30, as viewed in Figure 3,is providedwith a lubricant fitting 34a for introduction of lubricantinto the axial passages 35a and the radial passages 35!: and to the ontheshaft 35.

seat on respective cylindrical end extensions of the crosshead 89 towhich they are secured by cap screws 42 which extend through centralbores of the piston and have threaded engagement with the crosshead. Ifdesired, the central bores of the pistons may be threaded to facilitateremoval thereof from the crosshead.

Each of the pistons 4| (Figures 2 and '7) is slidably disposed within apacking member "48 including a cylindrical packing portion 44 ofsuitable oil and acid resistant rubber, such as synthetic rubber, bondedon a sleeve 45 which is provided with .roughened or knurled outer andinner surfaces at one end to insure a firm bond. The sleeve 45 isthreaded at its other endior engagement within a threaded portion of acylinder,head or closure 46 secured on the cylinder case M by suitablebolts 4'! and with a suitable sealing ring interposed. There are twobolts in number for each head 46 as seen in Figure 5. Adjacent. itsthreaded end, the sleeve 45 is provided with a suitable array of liquidtransmitting holes. The packing element or portion 44, as seen clearlyin Figure '7, is provided with a cupfaced end surface 44a. at each endthereof to provide annular sets of opposite pressure-responsive sealinglips. The packing portion 44 is also provided with annular taperingrecesses adjacent each end face 44a, and with centrally located outerand inner annular recesses 44b and No. The outer and inner annularrecesses 44b and 440 are joined by a series of radial apertures 44dwhich extend through the sleeve 45. Preferably, the central or bearingsurfaces of the packing portion 44 at either side of the annularrecesses 44b and 440 are formed of resilient material of a harder typethan the end or sealing surfaces 44a. The packing 44 fits within thecylinder wall 5| which at one side is apertured to receive a lubricantfitting 52 (Figures 1 and 4) so that lubricant can be introduced intothe annular recesses 44b and 440 for lubrication ofthe packing.

Each cylinder space of the cylinder case Ii is providedwith an inletpassage 56 (Figure 6) which leads to a check valve chamber 51 formed ina boss 58 in the casting and having the end openings therein closed byplugs 59. The reduced diameter within the boss 58 provides a taperedmounting or seat for a tapered annular valve seat member 6| of stainlesssteel or other suitable material having a rounded upper end surface onwhich a poppet valve 62 is seated normally under the urgency of a spring63. As seen more clearly in Figure 8, the valve 62 is formed of a metalbody member 62a having a central turned portion to receive the spring 68withan annular spring seat at the base of the turned portion withinwhich the end coil or the spring 63 engages. The spring 63 is seatedatits other end in a recess of the adjacent plug 59 and'serves to centerthe valve 62 on the valve seat 6| as well as to urge the valve againstthe seat. The valve 62 also includes a rubber facing or portion 62bwhich is bonded to a knurled face of the body 4 within the valve seat 6|and is of streamlined contour to provide a smoothly and uniformlydirectedfiow of liquid past the valve when it is lifted from the seat.

Each inlet check valve chamber 61 (Figures 2. I

3 and 4) communicates below its valve 62 with a longitudinally extendingintake passage 66 by -means of which liquid can be introduced throughone or more of a pair of tapped openings 81 leading to the passage 66.This passage 66 is common toboth of the piston and cylinder arrangementsof the pump.

To provide for discharge of liquid from each of the cylinders, adischarge passage 68 (Figures 2 and 3) is provided to which each of thecylinders has communication through a check valve 62 of the constructionand previously described in connection with the intake check valve. Thedischarge passage or chamber 68 is provided with a pair of tapped outletopenings 69.

It will be noted with reference to Figures 2 and 3 that the crank caseI8 is provided with oppositely disposed mounting pads Illa by means ofwhich the pump is mounted in upright position, and means is provided forshielding the crankcase from leakage fluid from the hydraulic system sothat the oil in the crankcase ill will not be contaminated. The top ofthe crankcase I0 is provided with a sheetmetal cover 1| having anupturned baflie wall or shield 12 disposed bellcrank. Cooperating withthe shield 12 is a depending baiile or shield 13 secured beneath thecrosshead 39 and freely telescoping or overlapping the shield 12 so thatany drainage liquid from the hydraulic system is effectively bailiedagainst entry within crankcase ID by virtue of the tortuous path itwould have to follow around the shields 13 and I2. Drainage liquid fromthe hydraulic system falls onto the cover H and is discharged throughone or more drainage openings 10 (Figure 2).

To provide for lubrication of the crosshead block 88 in its relativemovement with respect to both the wrist pin 31 and the crosshead 39, thecrosshead 39 is provided with a recessed lubricant fitting 1B (Figure 4)adapted for alignment with an opening 11 in the cylinder case II. Theopening 11 normally is closed by a spring cap I8. The lubricant fitting16 communicates with the wrist pin 31.

portion 62a and also within a central recess therein. To guide the flowof liquid the rubber portion 62b is provided with acentral conicallyshaped projection or tip which extends down In operation of the abovepump, upon transmission of a drive to the drive pinion l8 and the drivegear I9, each piston 4| is operative during its suction stroke to drawliquid into the associated cylinder past its intake check valve 62 andthen, upon the pressure stroke. to effect discharge of this liquid pastits discharge valve 62. It will be noted that the cylinders alternatelyload and unload. In the dead center position of partsshown in Figure 2the axis of the wrist pin 81 is slightly above the longitudinal axis ofthe istons, and, at the end of its movement in either direction, thewrist pin axis moves slightly below thepiston axis by an equal amount.This amount of movementis insufficient tointerrupt lubrication betweenthe lubricant passages 18 and 8|.

During the suction stroke of a piston the cupfaced end 44a of thepacking element 44 remote from the sleeve 45 expands under atmosphericpressure to press the annular lips against the piston and cylinder wall,respectively, and prevent introduction of air into the cylinder. Uponthe pressure stroke, the cup-faced end of the packing which isinterrupted by the sleeve 45 is flattened out so that its lips preventleakage of liquid during such pressure stroke.

It will be noted that the above replaceable packing constructionprovides for removal of the packing (by removing the two bolts 41) withthe head 46. Then by unscrewing the sleeve 45 from the head 46 andreplacing the worn packing assembly with a new one, the reverseoperations can be performed to install the new packing and cylinderhead.

The above pump construction is especially useful in high pressurehandling of abrasive liquids, such as spray liquids for use againstinsect pests.

Figure 2-A shows a modified form of drive connection between thecrosshead 39 and the operating bellcrank 33 therefor. In thisconstruction, the wrist pin 31 carries a roller or ball bearing 40 whichis interposed between a pair of hardened buttons 40a, and the buttons49a are mounted preferably in offset or eccentric relation to the bearin40. In this way the bearing will impart an oscillatory or rotativemovement to the buttons to distribute the wear. If desired, one or moreof the buttons 40a may be provided with a lubricant passage (not shown).The buttons 40a may also be employed in conjunction with the drive block38 if desired. Also, shims may be employed beneath the buttons tocompensate for wear.

While I have shown and described certain preferred embodiments of theinvention, it can be embodied in other forms and its scope should belimited only by the claims appended hereto.

I claim:

1. In a pump, a cylinder, a cylinder closure, a piston within thecylinder and spaced from the wall of the cylinder, and a packing memberinterposed between the cylinder wall and the piston in sealing relationtherewith and connected to the closure for insertion and removaltherewith.

2. In a pump, a cylinder, a cylinder head, a piston within the cylinderand spaced from the wall of the cylinder, and a packing memberinterposed between the cylinder wall and the piston in sealing relationtherewith and mounted on the cylinder head for insertion and removaltherewith.

3. In a pump, a cylinder, a cylinder closure, a piston within thecylinder and spaced from the wall of the cylinder, and a packing memberinterposed between the cylinder wall and the piston in sealing relationtherewith. said packing member comprising a sleeve detachably connectedto the closure and a resilient packing element carried by the sleeve.

4. In a pump, a cylinder, a cylinder closure, a piston within thecylinder and spaced from the wall of the cylinder, and a packing memberinterposed between the cylinder wall and the piston in sealing relationtherewith, said packing member comprising a slee e detachably connectedtothe closure and a resilient packing element bonded about one end ofthe sleeve.

5. In a pump, a cylinder, a cylinder closure, a piston within thecylinder and spaced from the wall of the cylinder, and a packing memberinterposed between the cylinder wall and the piston in sealing relationtherewith, said packing member comprising a sleeve detachably connectedto the closure and a resilient packing element carried by the sleevehaving cup-faced ends providing pressure-responsive sealing lips.

6. In a pump, a cylinder, a cylinder closure, a piston within thecylinder and spaced from the wall of the cylinder, a packing memberinterposed between the cylinder wall and the piston in sealing relationtherewith and connected to the closure for insertion and removaltherewith, an annular groove on the inner surface of said packingmember, and lubricating passage means leading through the wall of saidcylinder an said packing member to said groove.

7. In a pump, a cylinder, a cylinder closure, 9. piston within thecylinder and spaced from the wall of the cylinder, a packing memberinterposed between the cylinder wall and the piston in sealing relationtherewith comprising a tubular support element connected to the closureand a resilient packing portion secured on the support element, anannular groove on the inner surface of said packing portion, andlubricating passage means leading through the wall of said cylinder andsaid packing member to said groove.

8. In a pump, a cylinder,-a cylinder closure, a piston within thecylinder and spaced from the wall 01' the cylinder, a packing memberinterposed between the cylinder wall and the piston in sealing relationtherewith comprising a tubular support element connected to the closureand a resilient packing portion secured on the support element,respective annular grooves on the inner and outer surfaces of saidpacking portion, passage means in said packing member connecting saidgrooves, and means for supplying lubricant to the outer annular groove.

9. In a pump, a cylinder, a cylinder closure, a. piston within thecylinder and spaced from the wall or the cylinder, and a packingstructure detachably connected to said cylinder closure and including asealing portion disposed inwardly from said cylinder closure andinterposed between the cylinder wall and the piston in sealing relationtherewith, said sealing portion including respective cup-faced ends ofresilient material providing pressure responsive sealing lips engagingsaid cylinder wall and said piston at both ends of the packingstructure.

ROY M. MAGNUSON.

REFERENCES CITED The following references are of record in the file oi!this patent:

UNITED STATES PATENTS Joy Mar. 25, 194'!

